WLF scored a major victory when the U.S. Supreme Court ruled on January 9, 2001, that the Congress did not give authority to the U.S. Army Corps of Engineers under the Clean Water Act to regulate the filling of isolated wetlands. On July 25, 2000, WLF filed a brief with the U.S. Supreme Court on behalf of itself and the Allied Educational Foundation, urging it to reverse a lower court decision upholding federal jurisdiction. A local government agency in Illinois purchased a 533-acre parcel of land to be used as a landfill. Originally, the U.S. Army Corps of Engineers determined that the parcel did not constitute “waters of the United States” under the Clean Water Act. However, the Corps changed its position and asserted jurisdiction over the isolated wetland when it was discovered that migratory birds were spotted on the property. WLF argued that the Corps’ so-called “migratory bird rule” exceeds the authority conferred on the federal government under the Commerce Clause.